The present invention relates to a method for producing a grinding foil made of plastic and having a grinding agent uniformly distributed and pressed in to enrich the surface of the foil, the grinding agent being a diamond powder, in particular, and the foil being provided for grinding cutting styli and pickups used for playback of information carriers in the form of record discs.
Grinding foils as well as methods for grinding to restore the original profile of a mechanical signal pickup and apparatus for performing the grinding method are already known and are disclosed, for example, in German Offenlegungsschrift (Laid-Open Application) No. 2,053,866.
In order to practice this profile grinding method, a flexible plastic foil is required which should have a thickness, for example, of approximately 100.mu., its surface containing grooves whose cross section corresponds to the desired shape of the pickup to be ground. This surface is provided with a finely distributed grinding agent, for example a diamond powder, which is embedded in its surface.
For the unprofiled grinding of cutting styli which are to be used for cutting modulated signal grooves into lacquer foils forming the preliminary versions, or originals, of picture or phonograph records, flexible plastic grinding discs are required that must have planar, unprofiled surfaces. These surfaces are also provided with an embedded grinding agent.
As has been found in practice, grinding foils suitable for the intended purpose must meet stringent requirements, particularly with respect to the adhesion and penetration depth of the grinding agent embedded in the surface of the grinding foil.